RE: amt
For the most part - they're absolute tanks; very tough and reliable.
While "old school air-start", I love mine; it just runs and runs. I'm using a pony -sized bottle, but instead of SCUBA, it's from an escape kit. This way, I can fill it at work or elsewhere and don't have to worry about curious dive-shop guys insisting I have a certification. Very easy to carry everything in a duffle bag.